WO2012140962A1 - Exhaust gas purification system for working machine - Google Patents

Abstract

The present invention provides an exhaust gas purification system for working machine, in which a warning for urging regeneration is more reliably given to an operator, and proper manual regeneration is performed, thereby enabling DPF damage to be prevented. When a PM sedimentation amount is larger than a predetermined value, a warning for urging manual regeneration is displayed on a display screen (6a). When manual regeneration is not performed even with warning display, and time (t1) elapses from display of regeneration warning, a first warning tone is output from a speaker (6c). When the operator recognizes the first warning tone, and operates a regeneration switch (38), regeneration control starts. When the operator can not recognize the first warning tone, and time (t2) elapses from the display of the regeneration warning, a second warning tone (warning tone stronger than the first warning tone) is output from the speaker (6c) in place of the first warning tone. When the operator recognizes the second warning tone, and operates the regeneration switch (38), the regeneration control starts.

Description

Exhaust purification system for work machine

The present invention relates to an exhaust gas purification system of a working machine, and in particular, the particulate matter contained in the exhaust gas is collected by the filter to purify the exhaust gas, and the particulate matter collected on the filter is appropriately incinerated and removed The exhaust gas purification system, which urges a warning so as to regenerate the

A working machine such as a hydraulic shovel is equipped with a diesel engine as its driving source. The amount of particulate matter (PM: particulate matter: hereinafter referred to as PM) emitted from the diesel engine is NOx, Regulations have been strengthened year by year with CO, HC, etc. In response to such regulations, an exhaust gas purification system is known which collects PM with a filter called a diesel particulate filter (DPF: Diesel Particulate Filter) to reduce the amount of PM discharged to the outside. In this exhaust gas purification system, when the PM deposition amount of the filter increases, the filter is clogged, which causes an increase in the exhaust pressure of the engine, which causes deterioration of fuel efficiency and the like, and hence the filter is trapped The collected PM is burned appropriately to remove the clogging of the filter and the filter is regenerated.

Regeneration of the filter is usually performed by using an oxidation catalyst. There are cases where the oxidation catalyst is disposed upstream of the filter, when it is directly supported by the filter, and in both cases, the exhaust temperature is oxidized to activate the oxidation catalyst in either case. It must be higher than the activation temperature of the catalyst. If the exhaust temperature is high enough, it will self-regenerate, but if the exhaust temperature is not sufficient and it can not regenerate itself, PM may not be fully incinerated and removed by self-regeneration, so the exhaust gas temperature is forced to activate the oxidation catalyst There is a technique called forced regeneration that raises the temperature to a temperature higher than that. In this forced regeneration, a method of performing secondary injection (post injection) to inject fuel in the expansion stroke after in-cylinder main injection of the engine to raise the temperature of exhaust gas, the exhaust pipe by the fuel injection device for regeneration provided in the exhaust pipe In addition to the method of injecting fuel into the exhaust flowing through the engine to raise the exhaust temperature, the engine load is increased by instructing the engine speed to increase the engine load and the engine load by the hydraulic load action. There is a method of increasing the temperature and raising the temperature of exhaust gas.

Further, the filter forced regeneration includes automatic regeneration that automatically starts regeneration, and manual regeneration that starts regeneration by an operator's operation input. Automatic regeneration is performed when the PM deposition amount reaches a threshold or when a predetermined time set in advance elapses. However, PM deposition may progress because automatic regeneration is not properly performed.

On the other hand, Patent Document 1 discloses a technique related to manual regeneration. The operator is warned (for example, a warning light) to urge manual regeneration, and when the operator operates the regeneration switch, regeneration starts.

By the way, work machines, such as a hydraulic shovel, are machines for work, such as excavating work, for example. The operator concentrates on the work and may not notice even if a warning for manual regeneration is given. In addition, there is a possibility that the importance of manual regeneration may be neglected because priority is given to task execution. Even if a warning to promote manual regeneration is given, PM will continue to be deposited if manual regeneration is not performed, and problems such as abnormal rise in the internal temperature of the filter and combustion of the DPF resulting therefrom due to combustion of a large amount of collected PM May cause.

Patent Document 1 discloses a prior art that changes the content of a warning based on the PM deposition amount. Specifically, at first, the warning light blinks slowly, but when PM deposition progresses and the possibility of DPF damage increases, the warning light blinks quickly. Although patent document 1 is related to the general vehicle aiming at driving | running | working, it is applicable to working machines, such as a hydraulic shovel. The operator recognizes the importance of the manual regeneration based on the change in the warning, and can appropriately prevent the DPF from being damaged by performing the manual regeneration properly.

JP 2005-299403 A

In both the manual regeneration and the automatic regeneration, the PM deposition amount is generally estimated by detecting a differential pressure across the filter and calculating based on the detected value of the differential pressure. Therefore, the accuracy of control based on the PM deposition amount depends on the accuracy of estimation of the PM deposition amount. In other words, if there is an error in the estimated deposition amount, appropriate warning changes can not be made. If the estimated amount of deposition is calculated more than the actual amount of deposition and the warning content is changed based on the estimated amount of deposition, the error acts on the safety side, but the estimated amount of deposition is calculated less than the actual amount of deposition, If the content of the warning is changed based on the estimated amount of deposition, a delay in determination occurs. Due to this delay in determination, appropriate manual regeneration is not performed (at the start of manual regeneration is delayed), which is a cause of DPF damage.

An object of the present invention is to provide an exhaust purification system of a working machine capable of preventing DPF damage by giving a warning for prompting an operator to perform regeneration more properly and performing appropriate manual regeneration.

(1) In order to achieve the above object, according to the present invention, a filter disposed in an exhaust system of an engine for collecting particulate matter contained in exhaust gas and incineration removal of particulate matter deposited on the filter A playback device for playing back the filter, a playback control device for controlling operation start / stop of the playback device, a playback switch for instructing the playback control device to start playback, and warning means for prompting operation of the playback switch. The exhaust purification system for a working machine further comprises an operating state judging means for judging an operating state of the working machine, and the warning means further comprises an operating state judging means operating state based on a first warning time point. It has a warning content change function to change the warning content based on the elapsed time being determined.

(2) In order to achieve the above object, according to the present invention, a filter disposed in an exhaust system of an engine for collecting particulate matter contained in exhaust gas, and incinerating and removing particulate matter deposited on the filter A playback device for playing back the filter, a playback control device for controlling operation start / stop of the playback device, a playback switch for instructing the playback control device to start playback, and warning means for prompting operation of the playback switch. The exhaust purification system for a working machine further comprises an operating state judging means for judging the operating state of the working machine, and the warning means further includes a warning sound output function for outputting a warning sound, and a reference time point of the first warning. The alarm sound changing function is provided to change the alarm sound when the time during which the operation state judging means judges that the operation state is operating has passed a set time.

In the prior art, the warning content is changed based on the estimated deposition amount, and if there is an error in the estimated deposition amount, there is a possibility that an appropriate warning change can not be made. Thus, by changing the warning sound based on the elapsed time, it is possible to change the warning sound more reliably without being affected by the error of the estimated accumulation amount. The operator recognizes the warning sound and performs appropriate manual regeneration to prevent the DPF from being damaged.

(3) In the above (2), preferably, the operation state determination means determines whether the operation state of the work machine is in the standby state or the work state, and the warning sound change function is in the standby state or the work state. Set a different set time.

At the time of standby, PM deposition may be more advanced than at the time of work, and when the warning sound is changed based on the work state corresponding setting time, the determination of the warning sound change is delayed. At the time of standby, by changing the warning sound based on the standby state corresponding setting time, the warning sound can be changed more reliably without delay in the determination.

(4) In the above (3), preferably, the work machine is an engine rotational speed detection device, a work device, an operation lever for commanding the operation of the work device, and a lock for validating the command of the operation lever A gate lock lever selectively operated to a release position and a lock position for invalidating a command of the control lever, and a pilot pressure detection sensor for detecting a pilot pressure generated by the control lever When the engine speed detecting device detects a speed more than the low speed idle speed and the gate lock lever is operated to the lock position, it is determined that the working state of the work machine is in the standby state. The engine speed detecting device detects a speed more than the low speed idle speed, and the gate lock lever is operated to the unlocking position, and When the pilot pressure detection sensor for detecting the pressure of a predetermined value or more, determines that the operating state of the working machine is in working state.

Thus, the warning sound change function can change the warning sound based on the work state corresponding setting time at the time of work, and can change the warning sound based on the standby state correspondence set time at the time of standby.

(5) In the above (2), preferably, the warning sound change function changes at least one of the volume of the warning sound, the sound quality, the length of the sound, and the number of warnings.

Thereby, the operator can recognize the change of the warning sound.

(6) In order to achieve the above object, according to the present invention, there is provided a filter which is disposed in an exhaust system of an engine and collects particulate matter contained in exhaust gas, and a deposition amount of particulate matter deposited on the filter. The present invention relates to a deposition amount detection means to be detected, a regeneration device for regenerating the filter by burning away particulate matter deposited on the filter, a regeneration control device for controlling operation start / stop of the regeneration device, and the regeneration control device. In an exhaust gas purification system of a working machine including a regeneration switch instructing regeneration start and a warning means for prompting the operation of the regeneration switch, the warning means has a warning sound output function of outputting a warning sound, and the accumulation amount detection It has a warning sound change function that changes the warning sound based on the accumulation amount detected by the means.

According to the present invention, it is possible to prevent the DPF from being damaged by warning the operator to perform regeneration more reliably and performing appropriate manual regeneration.

FIG. 1 is a diagram showing an entire configuration of an exhaust gas purification system (first embodiment). It is a figure which shows the hydraulic circuit mounted in a hydraulic shovel. It is a figure which shows the external appearance of a hydraulic shovel. It is a figure which shows the functional block of a controller. It is a flowchart which shows the content of the arithmetic processing of a controller. It is a figure explaining the subject in a 1st embodiment. It is a figure explaining the structure and effect | action of 2nd Embodiment.

First Embodiment
Hereinafter, a first embodiment of the present invention will be described using the drawings.

~ Configuration ~
FIG. 1 is a view showing the overall configuration of an exhaust gas purification system for a working machine according to the present embodiment of the present invention.

A work machine (for example, a hydraulic shovel) is equipped with a diesel engine 1, and the engine 1 is provided with an electronic governor 1a which is an electronic fuel injection control device. The target rotation speed of the engine 1 is instructed by the engine control dial 2, and the actual rotation speed of the engine 1 is detected by the rotation speed detection device 3. The command signal of the engine control dial 2 and the detection signal of the rotational speed detector 3 are input to the controller 4, and the controller 4 controls the electronic governor 1a based on the command signal (target rotational speed) and the detection signal (actual rotational speed). It controls and controls the number of rotations and torque of the engine 1.

In addition, a key switch 5 is provided as a start / stop command device of the engine 1, and a command signal of the key switch 5 is also input to the controller 4, and the controller 4 controls the start and stop of the engine 1 based on the command signal. The key switch 5 also operates as a power supply start / stop instruction device for the controller 4 and the display device 6.

The control levers 28, 29 (see FIG. 2) and the gate lock lever 7 are provided in the cabin 107 of the hydraulic shovel. The gate lock lever 7 is selected to a first position A (locked release position) which is a lowered position for limiting the entrance of the driver's seat 108 and a second position B (locked position) which is a raised position for opening the entrance of the driver's seat 108 Operation is possible. The gate lock lever 7 has a position detection sensor 8 that detects its operation position.

The exhaust gas purification system is disposed in an exhaust pipe 31 constituting an exhaust system of the engine 1 and includes a filter 32 for collecting particulate matter contained in exhaust gas and an oxidation catalyst 33 disposed on the upstream side of the filter 32 A device 34, a differential pressure detection device 36 for detecting an upstream and downstream differential pressure (pressure loss of the filter 32) upstream and downstream of the filter 32, and an exhaust temperature installed upstream of the filter for detecting exhaust gas temperature A detection device 37, a regeneration switch 38 for instructing regeneration start, and a regeneration fuel injection device 39 provided between the engine 1 of the exhaust pipe 31 and the DPF device 34 and raising the temperature of the exhaust gas are provided. The oxidation catalyst 33 and the fuel injection device 39 for regeneration incinerate and remove PM (particulate matter) deposited on the filter 32 to constitute a regeneration device for regenerating the filter 32.

The regeneration switch 38 is disposed at a position where the operator in the cabin 107 of the hydraulic shovel can easily operate, and is operation means for instructing the start of operation of the regeneration fuel injection device 39 (start of regeneration of the filter 32). When 38 is operated to the ON position, a command signal instructing start of reproduction is output. The reproduction switch 38 may be a setting screen displayed on the display device 6. The operation switch 6b is operated to set ON / OFF.

The display device 6 is disposed at a position where the operator in the cabin 107 of the hydraulic shovel can easily view, and basically displays the basic information of the hydraulic shovel vehicle body such as the remaining amount of fuel and the cooling water temperature. The display device 6 has a display screen 6a, an operation switch 6b and a speaker 6c, and is controlled by a display controller 43 (see FIG. 4) of the controller 4. The operation switch 6b is disposed below the display screen 6a, and by operating the operation switch 6b, vehicle body information other than the vehicle body basic information is also selectively displayed. The display screen 6a and the operation switch 6b have a function as an interface. That is, the operator can perform various settings related to the vehicle body by operating the operation switch 6b while viewing the display screen 6a.

Further, as appropriate, the display device 6 also displays information related to reproduction of the vehicle body information, such as a notification that automatic regeneration control is being performed, a warning prompting the user to operate the regeneration switch 38, and the like. The speaker 6c may output the contents of the display screen 6a by voice.

In the present embodiment, when the manual reproduction is not properly performed, the speaker 6 c outputs a warning sound (detailed below).

FIG. 2 is a diagram showing a hydraulic circuit mounted on a construction machine (for example, a hydraulic shovel). The hydraulic circuit includes a variable displacement main hydraulic pump 11 and a fixed displacement pilot pump 12 driven by the engine 1, a hydraulic motor 13 and a hydraulic cylinder 14 driven by pressure oil discharged from the hydraulic pump 11, And 15 include pilot operated flow control valves 17 to 19 for controlling the flow (flow rate and direction) of the hydraulic fluid supplied from the hydraulic pump 11 to the hydraulic motor 13 and the hydraulic cylinders 14 and 15. A plurality of flow control valves and pressure of pressure oil discharged from the pilot pump 12 are kept constant, and a pilot relief valve 21 forming the pilot hydraulic pressure source 20 and an upper limit of the discharge pressure of the main hydraulic pump 11 are defined. The relief valve 22 is connected to the downstream side of the pilot hydraulic pressure source 20 and provided at the driver's seat entrance of the hydraulic shovel. The flow control valve is connected to the electromagnetic switching valve 23, which is ON / OFF controlled by the open / close position of the gate lock lever 7, and the pilot oil passage 24 on the downstream side of the electromagnetic switching valve 23. The remote control valves 25, 26, 27 for generating control pilot pressures a through f for operating 17 through 19 are provided.

The hydraulic pump 11 tilts the hydraulic pump 11 so that the absorption torque (consumption torque) of the hydraulic pump 11 does not exceed the maximum absorption torque which is a predetermined value based on the discharge pressure (the amount of inclination of the swash plate; It has a regulator 11a that controls the displacement or volume).

The remote control valves 25, 26, 27 are operated by left and right operation levers 28, 29 provided on the left and right of the driver's seat 108 (see FIG. 1). The control levers 28 and 29 are each operable in the cross direction, and the remote control valve 25 is operated when the control lever 28 is operated in one direction of the cross, and the remote control valve 27 is operated when the control lever 28 is operated in the other direction of the cross. When the operation lever 29 is operated in one direction of the cross, the remote control valve 26 is operated. When the operation lever 29 is operated in the other direction of the cross, a remote control valve (not shown) is operated. Further, when operating the control lever 28 in one direction of the cross, when operated in one direction from the neutral position, the remote control valve 25 generates the control pilot pressure a, and when operated in the opposite direction from the neutral position, the remote control valve 25 is generated generate b. The control pilot pressure a, b is led to the corresponding pressure receiving portion of the flow control valve 17 via the respective pilot lines 25a, 25b, whereby the flow control valve 17 is switched from the neutral position.

Similarly, when operating the control lever 28 in the other direction of the cross, the remote control valve 27 generates the control pilot pressure e when operated in one direction from the neutral position, and when operated in the opposite direction from the neutral position The pressure f is generated, and the control pilot pressures e, f are led via the respective pilot lines 27a, 27b to the corresponding pressure receiving part of the flow control valve 19, whereby the flow control valve 19 is switched from the neutral position. When operating the control lever 29 in one direction of the cross, operating in one direction from the neutral position generates control pilot pressure c, and operating in the opposite direction from the neutral position generates control pilot pressure d, control pilot pressure c, d is led via the respective pilot line 26a, 26b to the corresponding pressure receiver of the flow control valve 18, whereby the flow control valve 18 is switched out of the neutral position.

The hydraulic circuit further includes a shuttle valve group 46 and a pressure sensor 47. The shuttle valve group 46 extracts the highest pressure among the control pilot pressures a to f of the remote control valves 26 to 27 and the control pilot pressure of the other operation means. The pressure sensor 47 is connected to the output port of the shuttle valve provided on the most downstream side of the shuttle valve group 46, detects the highest pressure of the control pilot pressure, and detects the presence or absence of the operation.

The control pilot pressures a to f are communicated / blocked based on the position of the gate lock lever 7.

When the gate lock lever 7 is at the first position A, the solenoid of the electromagnetic switching valve 23 is excited to switch the electromagnetic switching valve 23 from the position shown in the drawing, and the pressure of the pilot hydraulic pressure source 20 is introduced to the remote control valves 25, 26, 27 Thereby, the flow control valves 17 to 19 can be operated by the remote control valves 25, 26, 27. When the gate lock lever 7 is raised to the second position B, the solenoid of the electromagnetic switching valve 23 is de-energized to switch the electromagnetic switching valve 23 to the position shown in the figure, and the pilot hydraulic pressure source 20 and the remote control valve 25, 26 The communication 27 is shut off, thereby making it impossible to operate the flow control valves 17 to 19 by the remote control valves 25, 26, 27. That is, when the gate lock lever 7 is raised to the second position B, the remote control valves 25, 26, 27 (control lever unit) are locked. When the gate lock lever 7 is again lowered to the first position A, the lock release state is established. To switch the position of the solenoid selector valve 23 by the gate lock lever 7, for example, a switch (not shown) is provided between the solenoid of the solenoid selector valve 23 and the power supply. When the gate lock lever 7 is at the first position A, the switch is used. When the gate lock lever 7 is operated to the second position B, the switch is turned off (opened) to cancel the excitation of the solenoid.

FIG. 3 is a view showing the appearance of the hydraulic shovel. The hydraulic shovel includes a lower traveling body 100, an upper swing body 101, and a front work implement 102. The lower traveling body 100 has left and right crawler type traveling devices 103a and 103b, and is driven by the left and right traveling motors 104a and 104b. The upper swing body 101 is swingably mounted on the lower traveling body 100 by a swing motor 105, and the front work implement 102 is attached to the front of the upper swing body 101 so as to be capable of raising and lowering. The upper revolving superstructure 101 is provided with an engine room 106 and a cabin 107, the engine 1 is disposed in the engine room 106, a gate lock lever 7 (FIG. 1) is provided at the entrance of a driver seat 108 in the cabin 107, and the driver seat A control lever unit (FIG. 2) incorporating remote control valves 25, 26 and 27 is disposed on the left and right of 108.

The front work machine 102 is an articulated structure having a boom 111, an arm 112, and a bucket 113. The boom 111 is pivoted up and down by the expansion and contraction of the boom cylinder 114, and the arm 112 is vertically and longitudinally by the expansion and contraction of the arm cylinder 115. The bucket 113 pivots up and down and in the front and back direction by the expansion and contraction of the bucket cylinder 116.

In FIG. 2, the hydraulic motor 13 corresponds to, for example, the swing motor 105, the hydraulic cylinder 14 corresponds to, for example, the arm cylinder 115, and the hydraulic cylinder 15 corresponds to, for example, the boom cylinder 114. The hydraulic drive system shown in FIG. 2 also includes other hydraulic actuators and control valves corresponding to the traveling motors 104a and 104b, the bucket cylinder 116, etc., but are not shown in FIG.

The work machine may be a wheel loader or a wheel type hydraulic shovel.

Control
FIG. 4 is a diagram showing functional blocks of the controller 4. The controller 4 includes a vehicle controller 41, an engine controller 42, and a display controller 43, which are mutually connected via a communication line 44 to configure a vehicle network. The command signal of the engine control dial 2, the detection signal of the position detection sensor 8 and the pressure sensor 47, and the command signal of the regeneration switch 38 are input to the vehicle controller 41, and the detection signal of the rotational speed detector 3 and the differential pressure detector 36 The detection signal of the exhaust gas temperature detection device 37 is input to the engine controller 42.

The vehicle controller 41 controls the entire vehicle such as a hydraulic drive. For example, by controlling the regulator 11 a of the hydraulic pump 11, the discharge pressure and the discharge flow rate of the hydraulic pump 11 are controlled. Besides, switching control of the electromagnetic switching valve 23 related to the gate lock is performed.

The engine controller 42 inputs a command signal of the engine control dial 2 through the communication line 44, and controls the number of rotations and torque of the engine 1 based on the command signal and the detection signal of the rotation number detector 3.

Further, the engine controller 42 inputs the detection signal of the differential pressure detection device 36 to estimate the PM deposition amount, performs the calculation processing of the regeneration control based on the estimated PM deposition amount, and according to the calculation result, the electronic governor 1a And control the fuel injection device 39 for regeneration (automatic regeneration control).

The display controller 43 inputs various signals and various arithmetic processing results via the communication line 44, sends it to the display device 6 as a display signal, and displays the information on the display screen 6a. In some cases, it is output to the speaker 6c as an audio signal. Further, a command signal from the operation switch 6b as a user interface is input.

Furthermore, the engine controller 42 has a manual regeneration control function 42a. The manual regeneration control function 42a receives the detection signal of the differential pressure detection device 36 to estimate the PM deposition amount, transmits a warning signal to the display controller 43 based on the estimated PM deposition amount, and sends a command signal for the regeneration switch 38. The electronic governor 1a and the fuel injection device 39 for regeneration are controlled via the communication line 44 (manual regeneration control).

As a characteristic configuration of the present embodiment, the vehicle controller 41 has an operation state determination function 41a, a warning sound change function 41b, and a memory 41c.

The operating state determination function 41a determines the operating state / non-operating state of the hydraulic shovel as follows, and further determines the standby state / working state among the operating states.

The operation state determination function 41a receives the detection signal of the rotation number detection device 3 through the communication line 44, and determines that the operation state is the actual engine rotation number if the actual engine rotation number is equal to or higher than the low speed idle rotation number. If it is less than the low speed idle rotation speed, it is determined that the non-operating state.

When the operating state is determined, the operating state determination function 41a receives the detection signal of the position detection sensor 8, and determines that the hydraulic shovel is in the standby state if it is in the locked state, and the detection signal of the position detection sensor 8 and the pressure sensor The detection signal of 47 is input, and in the unlocked state, if it is a predetermined pilot pressure or more, it is determined that the working state of the hydraulic shovel.

The warning sound change function 41b sets the set times t1, t2 and t3 (t1 <t2 <t3) based on the determination result of the operation state determination function 41a. When the determination result is the standby state, the set time corresponding to the standby state is read from the memory 41c, and when the determination result is the work state, the set time corresponding to the work state is read from the memory 41c. The set times t1, t2 and t3 corresponding to the standby state are set shorter than the set times t1, t2 and t3 corresponding to the work state.

When the warning sound change function 41b receives the warning signal of the manual regeneration control function 42a, the warning sound change function 41b measures an elapsed time with this as a reference time point.

When the elapsed time exceeds the set time t1, the warning sound change function 41b reads the voice data of the first warning sound from the memory 41c, and outputs it to the display controller 43 as a voice signal. When the elapsed time exceeds the set time t2, the voice data of the second warning sound is read from the memory 41c and is output as a voice signal to the display controller 43. When the elapsed time exceeds the set time t3, the third warning sound from the memory 41c. The audio data of is read out and output to the display controller 43 as an audio signal.

FIG. 5 is a flowchart showing the content of the arithmetic processing of the controller 4.

First, manual regeneration control will be described. Although the manual regeneration control is performed in parallel with the automatic regeneration control, the description of the process of the automatic regeneration control is omitted for simplification of the description.

It is determined whether the estimated deposition amount based on the detection signal of the differential pressure detection device 36 is larger than the first threshold which is the manual regeneration start warning value (step S11), and it is determined that the estimated deposition amount is not larger than the first threshold. The process of step S11 is repeated until the estimated deposition amount becomes larger than the first threshold.

In step S11, when it is determined that the estimated deposition amount is larger than the first threshold value, a warning signal for urging the operator to operate the regeneration switch 38 is output. As a result, a warning to prompt manual reproduction is displayed on the display screen 6a (step S12).

Then, it is judged whether or not the reproduction switch 38 is operated (reproduction switch ON) (step S13), and when it is judged that the reproduction switch 38 is not operated (reproduction switch OFF), the reproduction switch 38 is operated. The warning display is continued until the warning sound is controlled (detailed below).

If it is determined in step S13 that the regeneration switch 38 has been operated (regeneration switch ON), manual regeneration control is started (step S13).

Reproduction control is performed, for example, as follows. First, the rotational speed of the engine 1 is controlled to a predetermined rotational speed Na suitable for forced regeneration control. The predetermined rotation number Na suitable for forced regeneration control is a medium rotation number capable of raising the temperature of the exhaust gas at that time to a temperature higher than the activation temperature of the oxidation catalyst 33. In this control, the vehicle controller 41 switches the target rotational speed of the engine 1 from the target rotational speed instructed by the engine control dial 2 to a predetermined rotational speed Na, and the predetermined rotational speed Na (target rotational speed) is transmitted to the communication line 44. Output to the engine controller 42. The engine controller 42 performs feedback control of the fuel injection amount of the electronic governor 1 a based on the target rotation number (predetermined rotation number Na) and the actual rotation number of the engine 1 detected by the rotation number detection device 3. The rotation speed is controlled to be the predetermined rotation speed Na.

Next, when it is confirmed that the exhaust gas temperature detected by the exhaust temperature detection device 37 has risen to a predetermined temperature (a temperature higher than the activation temperature of the oxidation catalyst 33), the regeneration fuel injection device 39 is controlled to exhaust Fuel injection into the pipe 31 is performed. By injecting fuel into the exhaust pipe 31, unburned fuel is supplied to the oxidation catalyst 33, the unburned fuel is oxidized by the oxidation catalyst 33, and the heat of reaction obtained at that time further raises the exhaust gas temperature. The PM deposited on the filter 32 is incinerated and removed. If necessary, the engine load may be increased and the temperature of the exhaust may be increased by an engine speed increase command or a hydraulic load action.

During regeneration control, it is determined whether the estimated deposition amount is less than the second threshold that can be regarded as a regeneration end value (step S15), and when it is determined that the estimated deposition amount is less than the second threshold, manual regeneration control is stopped ( Step S16). If it is determined in step S15 that the estimated deposition amount is not less than the second threshold, the regeneration control is continued until the estimated deposition amount is less than the second threshold.

When stopping the regeneration control, the target rotation number is returned to the target rotation number (low idle rotation number) instructed by the engine control dial 2, and the control of the regeneration fuel injection device 39 is stopped. Instead of returning the target rotational speed to the target rotational speed (low idle speed) indicated by the engine control dial 2, the engine 1 may be stopped.

Next, control relating to the warning sound will be described.

The operation state of the hydraulic shovel is determined in advance (step S21), and set times t1, t2 and t3 are set based on the determination result (whether the operation state is the standby state or the work state) (step S22).

When a warning is displayed in step S12 to prompt manual regeneration, measurement of the elapsed time is started on the basis of the warning display time (step S23).

First, it is determined whether the elapsed time exceeds the set time t1 (step S24). If it is determined that the set time t1 has not elapsed, the process proceeds to step S13 until the regeneration switch 38 is operated or the set time t1 elapses. , The process of step S24 is repeated. If it is determined that the set time t1 has elapsed, the first warning sound is output (step S25).

Next, it is determined whether or not the elapsed time exceeds the set time t2 (step S26). If it is determined that the set time 2 has not elapsed, the step is performed until the regeneration switch 38 is operated or the set time t2 elapses. The processes of S13, step S24 and step S25 are repeated, and the first warning sound output is continued. If it is determined that the set time t2 has elapsed, a second warning sound is output in place of the first warning sound (step S27).

Further, it is determined whether the elapsed time exceeds the set time t3 (step S28). If it is determined that the set time t3 has not elapsed, the process proceeds to step S13 until the regeneration switch 38 is operated or the set time t3 elapses. , And repeat the processing of step S24 to step S27 to continue the second warning sound output. If it is determined that the set time t3 has elapsed, the third warning sound is output in place of the second warning sound (step S29).

If it is determined in step S13 that the regeneration switch 38 has been operated (regeneration switch ON), manual regeneration control is started (step S13). On the other hand, if the regeneration is not performed even after a predetermined time has elapsed after the third warning sound is output, the excessively deposited PM burns rapidly, and the filter temperature may abnormally rise and damage the filter. Prohibit (not shown for separate control).

-Correspondence with the claims-
In the present embodiment, the process of step S12 of the manual regeneration control function 42a, the display controller 43, and the display screen 6a constitute warning means for prompting the user to operate the regeneration switch 38.

The process of step S21 of the rotation speed detection device 3, the position detection sensor 8, the pressure sensor 47, and the operation state determination function 41a constitutes an operation state determination means for determining the operation state of the work machine.

In the processing of steps S23 to S29 of the warning sound change function 41b, the warning sound change function changes the warning sound when the time when the operation state is determined with reference to the warning display time point prompting manual reproduction has passed a set time. Configure

~ Operation ~
(1) The basic operation of the exhaust gas purification system of the present embodiment will be described.

During operation of the hydraulic shovel, automatic regeneration control is performed. However, if the automatic regeneration is not properly performed for some reason, PM deposition proceeds. When the PM deposition amount becomes larger than the first threshold value, a warning that prompts manual regeneration is displayed on the display screen 6a. When the operator operates the regeneration switch 38, regeneration control starts. When the deposited PM is burned and removed, and the PM deposition amount becomes larger than the second threshold, the regeneration control is stopped (S11 → S12 → S13 → S14 → S15 → S16).

By the way, a hydraulic shovel is a machine for working such as excavating work. The operator concentrates on the work and may not notice even if a warning for manual regeneration is given. In addition, there is a possibility that the importance of manual regeneration may be neglected because priority is given to task execution. Even if a warning to promote manual regeneration is given, PM will continue to be deposited if manual regeneration is not performed, and problems such as abnormal rise in the internal temperature of the filter and combustion of the DPF resulting therefrom due to combustion of a large amount of collected PM May cause.

When the time t1 has elapsed (the time t2 has not elapsed) from the reproduction warning display, the first warning sound (for example, the volume is low, the normal sound, the short sound 3 times, a pop) is output from the speaker 6c. When the operator recognizes the first warning sound and operates the reproduction switch 38, reproduction control starts (S12 → S23 → S24 → S25 → S26 → S26 → S13 → S14).

However, in construction sites where hydraulic excavators are used, other construction work is often performed in parallel, and there is a possibility that the operator may not recognize the first warning sound because the work sound is extinguished. When time t2 elapses (does not elapse time t3) from the playback warning display, it changes to the first warning sound, and the second warning sound from the speaker 6c (for example, during volume, bass, 5 long intermittent tones, boo, boo, boo Boo Boo Boo) is output. When the operator recognizes the second warning sound and operates the playback switch 38, playback control starts (S25 → S26 → S27 → S28 → S13 → S14).

If manual regeneration is not performed even if the second warning sound is output, the operator is strongly urged to perform manual regeneration. When time t3 elapses from the reproduction warning display, the sound changes to the second warning sound, and the third warning sound (for example, loud volume, deep bass, continuous sound, buzz) is output from the speaker 6c. When the operator recognizes the third warning sound and operates the playback switch 38, playback control starts (S25 → S26 → S27 → S28 → S13 → S14).

If manual regeneration is not performed even if the third warning sound is output, the PM deposited excessively after a predetermined time has elapsed may burn rapidly, and the filter temperature may abnormally rise and damage the filter. Prohibit

The above basic operation has been described on the assumption that the hydraulic shovel is working. When it is determined that the hydraulic shovel is in the working state, set times t1, t2 and t3 corresponding to the working state are set (S21 → S22).

(2) The operation of the exhaust gas purification system at the time of standby of the hydraulic shovel will be described.

By the way, there is a dump truck loading operation of excavated soil as one of the operations of a hydraulic shovel. Organize excavated soil in one place and load it on a waiting dump truck. Dumper carries out the excavated soil out of the site. If the number of dump trucks is small, the hydraulic shovel waits until the next dump truck comes.

When the hydraulic shovel is in the standby state, the exhaust gas temperature drops sharply, so that self-regeneration and automatic regeneration are not properly performed, and there is a possibility that PM deposition may progress more than in work.

When it is determined that the hydraulic shovel is in the standby state, set times t1, t2 and t3 corresponding to the standby state are set (S21 → S22). The set times t1, t2 and t3 corresponding to the standby state are respectively set shorter than the set times t1, t2 and t3 corresponding to the work state. Therefore, at the time of standby of the hydraulic shovel, the first to third warning sounds are outputted earlier than at the time of work. When the operator recognizes the warning sound and operates the playback switch 38, playback control starts.

(3) If the engine 1 is stopped while the warning sound is output, all control is interrupted. The elapsed time at this time is stored in the memory 41c. When power is supplied to the controller 4 and the display 6 again by the key switch 5, the previous elapsed time is read, and a warning sound is output even before the engine is started.

~ Effect ~
(1) The first warning sound is a weak warning if the elapsed time is short with reference to the warning display prompting manual regeneration and the possibility of DPF damage is relatively low (compared to the description below) It is output. Since the first warning sound is a weak warning, the operator does not feel bothersome. On the other hand, it is possible to prevent the DPF from being damaged by the operator recognizing the first warning sound and performing appropriate manual regeneration.

Manual regeneration is not performed even by the first warning sound output, and as the elapsed time becomes longer, the possibility of DPF breakage increases. Instead of the first warning sound, the second warning sound, which is a stronger warning, and the third warning sound, which is a stronger warning, are output. Since the second warning sound and the third warning sound are strong warnings, the operator can reliably recognize the second warning sound and the third warning sound and perform appropriate manual reproduction to prevent the DPF from being damaged.

(2) In the prior art, the warning content is changed based on the estimated deposition amount, and if there is an error in the estimated deposition amount, there is a possibility that an appropriate warning change can not be made. In particular, when the estimated deposition amount is calculated to be smaller than the actual deposition amount and the warning content is changed based on the estimated deposition amount, the determination of the warning content change is delayed, and this delay prevents appropriate manual regeneration from being performed. There is a problem that it is a cause of DPF damage (delay in starting manual regeneration).

In the present embodiment, the warning sound is changed based on the elapsed time, and the warning sound can be more reliably changed without being affected by the error of the estimated accumulation amount. The operator recognizes the warning sound and performs appropriate manual regeneration to prevent the DPF from being damaged.

(3) The hydraulic shovel is a machine for performing work such as excavating work, and it is premised that it is in working state, but depending on the contents of work, the standby state may be continued. At the time of standby, PM deposition may be more advanced than at the time of work, and when the warning sound is changed based on the work state corresponding setting time, the determination of the warning sound change is delayed.

In the present embodiment, at the time of standby, the warning sound can be changed more reliably without delay in the determination by changing the warning sound based on the standby state corresponding setting time. The operator recognizes the warning sound and performs appropriate manual regeneration to prevent the DPF from being damaged.

~ Modification ~
(1) In the present embodiment, the warning sound may be a first warning sound (for example, low volume, normal sound, 3 shorts, pop-up) → second warning sound (for example, middle volume, bass, Change like 5 long intermittent tones, boo boo boo boo boo) → 3rd warning tone (eg loud volume, deep bass, continuous tone, boo), but this is an example of warning tone change Yes, the volume of the warning sound, the sound quality, the length of the sound, the number of warnings, etc may be changed as appropriate.

(2) In the present embodiment, the warning display (step S12) for prompting manual regeneration is performed based on the estimated amount of deposition by the differential pressure detection device 36, but the influence of the error of the estimated amount of deposition is eliminated It may be performed based on the elapsed time from the start of work.

(3) In the present embodiment, the warning sound is changed based on the elapsed time based on the warning display time point, but if the estimation accuracy of the estimated deposition amount is high, the warning sound is changed based on the estimated deposition amount You may

(4) In the present embodiment, the warning sound is changed based on the elapsed time, but the warning display displayed on the display screen 6a may be changed to a more alert display.

Second Embodiment
~ Issues ~
The operation of the exhaust gas purification system when returning from the standby state to the working state during control in the first embodiment will be described. At the time of standby, PM deposition may progress more than at the time of operation. Therefore, when it is determined that the hydraulic shovel is in the working state, and the setting times t1, t2 and t3 corresponding to the working state are set again, the setting times t1 and t2 corresponding to the working state are determined based on the elapsed time measured during standby. The change of the warning sound is actually delayed compared to t3.

Further details will be described using FIG. FIG. 6 is a conceptual diagram for explaining an outline of the problem caused by the setting time being different between the standby state and the working state. The horizontal axis is time, and the vertical axis is the deposition amount. The alarm deposition noise amount to be changed is defined as a threshold value Q, and the corresponding work condition setting time is represented by T to indicate the progress of PM deposition during operation. Then, at the time of standby, PM deposition proceeds X times (X is a positive number larger than 1) compared to at the time of operation, and indicates PM deposition progress at the time of standby. Therefore, it is assumed that the standby state corresponding setting time (corresponding to the threshold value Q) is set to the reciprocal multiple of X (= T / X) with respect to the work state corresponding setting time T.

The dotted line indicates the progress of PM deposition when returning from the standby state to the working state at point A in the figure. At point A in the figure, when it is determined that the hydraulic shovel is in the working state, the working state corresponding setting time T is set again. On the other hand, before the measurement time passes the working state corresponding setting time T, the threshold Q is reached at point B in the figure. That is, it is late if the warning sound is changed when the working state corresponding setting time T has elapsed.

~ Configuration / Effect ~
In this embodiment, an elapsed time conversion function 41d (additional to FIG. 4) is added to the warning sound change function 41b of the first embodiment.

FIG. 7 is a conceptual diagram for explaining the operation outline of the elapsed time conversion function 41d. As in the case of FIG. 6, assuming that the operation returns from the standby state to the working state at point A in the figure, the elapsed time at point A in the figure is t.

The elapsed time conversion function 41d calculates the point C on the line indicating the progress of PM deposition during operation so as to be the same amount as the amount of deposition at the point A in the figure. In FIG. 7, the conversion elapsed time at point C in the drawing is Xt. The conversion elapsed time is an elapsed time when it is assumed that the working state is from the reference time.

When the measured elapsed time is t, the warning sound change function 41 b considers that only the converted elapsed time Xt has elapsed, and continues the time measurement. Then, when the elapsed time exceeds the work state corresponding setting time T (corresponding to the threshold Q), the warning sound is changed.

In the present embodiment, by providing the elapsed time conversion function 41d, even when the standby state is returned to the working state, the warning sound can be more reliably changed without delay in the determination. The operator recognizes the warning sound and performs appropriate manual regeneration to prevent the DPF from being damaged.

On the other hand, when the work state changes to the standby state, the elapsed time conversion function 41d calculates a converted elapsed time t / X when the measured elapsed time is t.

Reference Signs List 1 diesel engine 1a electronic governor 2 engine control dial 3 rotational speed detector 4 controller 5 key switch 6 display 6a display screen 6b operation switch 6c speaker 7 gate lock lever 8 position detection sensor 11 hydraulic pump 12 pilot pump 13 hydraulic motor 14, Reference Signs List 15 hydraulic cylinder 17 to 19 flow control valve 20 pilot hydraulic source 21 pilot relief valve 22 main relief valve 23 solenoid switching valve 24 pilot oil passages 25, 26 and 27 remote control valves 28 and 29 operation lever 31 exhaust pipe 32 filter 33 oxidation catalyst 34 DPF device 36 Differential pressure detection device 37 Exhaust temperature detection device 38 Regeneration switch 39 Regeneration fuel injection device 41 Vehicle controller 41a Operation state determination function 41b Warning sound change function 41c Memory 41d Elapsed time conversion Function (second embodiment)
42 engine controller 42a manual regeneration control function 43 display controller 44 communication line 46 shuttle valve group 47 pressure sensor 100 lower traveling body 101 upper revolving body 102 front working machine 103a, 103b crawler type traveling device 104a, 104b traveling motor 105 revolving motor 106 engine Room 107 Cabin 108 Driver's seat 111 Boom 112 Arm 113 Bucket 114 Boom cylinder 115 Arm cylinder 116 Bucket cylinder

Claims (6)

A filter (32) disposed in the exhaust system of the engine (1) for collecting particulate matter contained in the exhaust, and a regenerating apparatus (33) for incinerating and removing the particulate matter deposited on the filter , 39), a reproduction control device (42) for controlling the start / stop of operation of the reproduction device, a reproduction switch (38) for instructing the reproduction control device to start reproduction, and warning means for prompting operation of the reproduction switch (6a, 42a, 43) in the exhaust gas purification system of a working machine,
The apparatus further comprises operation state determination means (3, 8, 41a, 47) for determining the operation state of the work machine,
The warning means further has a warning content change function (41b) for changing the warning contents based on an elapsed time in which the operation state determination means determines the operation state with reference to the first warning time point. Exhaust purification system of the working machine. A filter (32) disposed in the exhaust system of the engine (1) for collecting particulate matter contained in the exhaust, and a regenerating apparatus (33) for incinerating and removing the particulate matter deposited on the filter , 39), a reproduction control device (42) for controlling the start / stop of operation of the reproduction device, a reproduction switch (38) for instructing the reproduction control device to start reproduction, and warning means for prompting operation of the reproduction switch (6a, 42a, 43) in the exhaust gas purification system of a working machine,
The apparatus further comprises operation state determination means (3, 8, 41a, 47) for determining the operation state of the work machine,
The warning means further includes a warning sound output function (6c) for outputting a warning sound;
A warning sound changing function (41b) is provided to change the warning sound when a time during which the operation state determination means determines that the operation state is determined on the basis of the first warning time has passed a set time. Exhaust purification system. In the exhaust gas purification system for a working machine according to claim 2,
The operation state determination means determines whether the operation state of the work machine is in a standby state or a work state,
The exhaust gas purification system for a working machine, wherein the warning sound change function sets a different set time depending on whether it is in a standby state or an operation state. In the exhaust gas purification system for a working machine according to claim 3,
The work machine includes an engine rotational speed detection device (3), a work device, an operation lever (28, 29) for commanding the operation of the work device, and an unlocking position and operation for enabling the command of the operation lever. A gate lock lever (7) selectively operated to a lock position at which a lever command is invalidated, and a pilot pressure detection sensor (47) for detecting a pilot pressure generated by the operation lever;
The operation state determination means is
When the engine rotation number detection device detects a rotation number equal to or higher than the low speed idle rotation number and the gate lock lever is operated to the lock position, it is determined that the operation state of the work machine is in the standby state.
When the engine rotation number detection device detects a rotation number higher than the low speed idle rotation number, and the gate lock lever is operated to the unlocking position, and the pilot pressure detection sensor detects a pressure higher than a predetermined value, It is determined that the operating state of the working machine is the working state. In the exhaust gas purification system for a working machine according to claim 2,
The exhaust gas purification system of a working machine, wherein the warning sound change function changes at least one of a volume of a warning sound, a sound quality, a length of a sound, and a number of warnings. A filter (32) disposed in the exhaust system of the engine (1) for collecting particulate matter contained in the exhaust, and a deposition amount detection means (36, for detecting the deposition amount of particulate matter deposited on the filter) 42), a regeneration device (33, 39) for incinerating and removing particulate matter deposited on the filter, and a regeneration control device (42) for controlling start / stop of operation of the regeneration device; In an exhaust gas purification system of a working machine, comprising: a regeneration switch (38) for instructing the regeneration control device to start regeneration; and warning means (6a, 42a, 43) for prompting operation of the regeneration switch,
The warning means is
With warning sound output function (6c) which outputs warning sound,
An exhaust gas purification system for a working machine, comprising a warning sound change function (41b) for changing a warning sound based on the accumulation amount detected by the accumulation amount detection means.

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